Combined gas burner and mixing apparatus



1931- H. B. BARBER ET AL 1,826,163

COMBINED GAS BURNER AND MIXING APPARATUS Filed Feb. 13, 1950 INVENTOR5= H. E). BARBER :HEP URN Patented- Oct. a, 1931,

UNITED STATESiPATENTl oFFlc-a HUGH B. BARBER AND WILLIAM I. HRPBURN, OI TOLEDO, OHIO, ASSIG INOR S '10 SUR- FACE COMBUSTION CORPORATION, 01 TOLEDO, OHIO, A CORPORATION OF YORK.

' COMBINED ens nuam' mm mxme muga rns Application madm n 12, mo. Serial 16:42am.

This invention relates to im rovements in gas burners for furnaces and as among its objects to provide a burner capable of forming and delivering, by using relatively low '6 pressure air as the gas entraming medium, a

mixture of air and gas, the relative propor tions of which shall remain substantiall constant over a relatively wide range turn down; to'provide a burner with which different kinds of fuel gas may be utilized with substantially equal advantage by simple ad justment of lcertain elements of the burner;

' burner and as to provide a {burner wherein all of the essential elements are contained within the burner case; to provide a simple means for controlling the supply of secondaryair to the mixture formed within the burner case; to rovide a simple means for controlling the ow of gas to the mixing tube and withal to provide a burner which shall be simple in construction and capable of manufacture at relatively low cost.

The'nature of derstood when described in connection with the accompanyingdrawings, in which: 1

Fig. 1 is a top plan of the improved burner; v

Fig. 2 is an end elevation of the gas and air inlet end thereof;

Fig. 3 is an axial section of the burner on line 3-3 of Fig.2;

Fig. 4 is a transverse section on line 4-4 of Fi 3 I %ig. 5 is an enlarged view of a detail of the Fig. 6 shows the improved burnerapplied to a furnace known in the art as a soakingapit. m

The burner is generally indicated at I Fig. 6 and is shownas positioned to discharge through a furnace wall 10 having an aperture wherein the discharge end of the burner may be positioned for discharging the combustible mixture into a combustion tunnel 12 openin into the furnace chamber C. In the case 0 a soaking pit as illustrated, it is desirable to provide an expansion flame chamber 14 in order that the highly heated gases may enter the ingot chamber with reduced velocity. 16 indicates a laterally movable roof for the pit; 18 the flue opemng and W the work or ingots to be heated. 20 indlcates the the invention will be best undescribed. The tube 32 adjacent t air supply pipe'alid-22 the gas supply pipe of the burner itself, it will be seen that there is provided a main casing 26 which is substantially circular in cross section, there be- 1ng provided a radial flange 28 intermediate the ends thereof to permit securement of the burner to the furnace'wall. The casing is an open-ended aflair, one end being closed by a removable cover plate 30 to permit insertion and removal and adjustment of a Venturi entrainin tube 32 which is threadedly mounted 1n a c ambered support 34, the chamber thereof being indicated at 36 and constitutng a as chamber into which fuel gas supplied y the gas pipe 22 is delivered after passlng through instrumentalities presently e nozzle end 38 of the casing 26 is circumferentially beveled as at 40 whereby, the tube may serve I as a valve for. restricting the flow of air through the adjacent end of the casing. The

' the discharge bore or nozzle of the casing an annular passage 44 for outflow of secondary air. For holding the tube 32 in adjusted'position the flange at the opposite end of the tube may be provided with a set screw 46 adapted for abutment against the adjacent wall of the chamber 36. i

The tube 32 is provided with a as intake shownas ports 33 slightly beyon its point of minimum cross section, these ports opening to the gas chamber 36. Air is delivered to the casing 26 under pressure and this air on passing through the tube 32 will entrain as at the intake 33 from the chamber 36 with the result that there will flow from the tube a mixture of air and gas. Ordinarily though not necessarily, the gas in the chamber 36 would be maintained at atmospheric pressure -ficient in air for complete combustion.

the casing at about one pound pressure, this pressure differential being sufiicient for proper operation of the apparatus.

A partition. separates the chamber 36 from the gas pipe 22, this partition being provided with an aperture whose upper end is beveledto form a seat for a hollow and apertured valve plug 52 which at its upper end is threadedly supported as at 54 1n a raised apertured portion of the casing 26, the top of said portion being preferably closed by a removable plate 56. Normally the plug 52 will be seatedagainst the partition 50 and gas from the pipe 22 will, therefore, pass through the apertures 58 in the plug and through the nozzle 60 thereof into the chamber 36. It will be noted that the nozzle is threadedly secured in the plug. This is to permit the use of difierent size nozzles depending on the B. t. 11. value of the gas which is available for use, the higher the B, t. u. value of the gas the smaller the orifice 1n the nozzle. When it is desired to change the nozzle, the plug is removed from the casing, the cover 56 being removable for this purpose.

The mode of operation of the apparatus may be described as follows; The pressure of the air delivered to the casing 26 by the air pipe 20 will always be in excess of the gas ressure in the gas pipe 22 by a suitable diferential, say one pound. The air passing through the tube 32 .Will entrain gas through the gas intake ports 33 from chamber 36, the gas intake ports being of such slze that the mixture issuing from the tube will contain an excess of gas or in other words will be idlee reason for forming a gas rich mixture is to enable the burner to be turned down low without causing flash-back of flame into the tube. The balance of the air required for complete combustion of the mixture leaving the tube 32 flows from within the casing 26 through the annular space 44 around the discharge end of said tube. By proper axial ad ustment of the tube 32, the amount of secondary air permitted to flow past the valve seat 40 can be controlled to a nicety.

The flow of gas into the chamber 36 is ordinarily controlled by the size of the orifice in nozzle 60. When a gas of relatively high B. t. u. value is to be used, a nozzle with relatively restricted orifice will be used, as indicated in Fig. 5, and when a gas of relatively low B. t. u. value is to be used, a nozzle with a relatively large orifice Will be used as indi cated in Fig. 3. Gas will be delivered to the inlet side of the nozzle 60 at a constant pressure and the amount of gas which flows through the nozzle will be dependent on the differential of pressure between the inlet and outlet sides of said nozzle. It will be readily apparent that by providing the proper size of orifice in the nozzle 60, the quality of the mixily controlled.

If at times it should be desired to produce a mixture materially richer in gas than would be produced by the flow of gas through the orifice in the nozzle 60, it is not necessary to change the nozzleto a larger size since by backing the plug 52 oil its seat, an additional flow passage will be provided as will be readily understood. It will be noted that the upper side of the plug) 52 is imperforate and hence the plug may e readily adjusted with respect to the partition seat without gas escaping into the atmosphere when the cover plate 56 is removed.

From the foregoing description it will be seen that the present invention provides a relatively simple and compact piece of apparatus containing within itself means for initially forming a gas-rich mixture of air and gas; means for controlling the amount of secondary air required to support combustron in the mixture; and means for readily varying the quality of the first formed mix ture. It will also be noted that relatively few machining operations are required on the easing 26 and that such as are required rel atively simple.

What is claimed is:

1. In apparatus adapted to utilize air under pressure to induce a flow of gas under lesser pressure, the combination with an entraining tube having a gas intake intermediate its ends, of a gas chamber wherein the gas intake portion of said tube is contained, a casing forming an air chamber about said tube and having a nozzle adjacent which the discharge end of the tube terminates, means for supplying gas to said gas chamber, means for supplying air to said air chamber, he space relationship between said nozzle and the adjacent end of the tube being such as to form a passage through which air from within the casing may flow for supporting combustion in the mixture issuing from said tube.

2. In apparatus as set forth in claim 1, said tube 'being axially adjustable With respect to said nozzle for controlling the flow of air through the nozzle.

3. In apparatus as claimed in claim 1, said tube being supported by the walls of said gas chamber.

4. In apparatus as claimed in claim 1, said .gas chamber being wholly within said casing,

and said tube being supported by the walls of said chamber.

5. In apparatus as claimed in claim 1, means between said gas-supplying means and the gas intake portion of said tube for controlling the flow of gas into said gas chamber.

6. In combination, an entraining tube having a gas intake intermedate its ends and a gas chamber in communication with said gas intake, means for controlling the ad- 'ture discharged from the tube can be readmission of gas to said chamber comprising a may flow through said from the gas chamber,

outlet, a gas-supply chamber an entrainingftube having a gas intake flow of gas into chambered body adapted to restrict the effective size of the gas inlet to said chamber, said body having a relatively restricted orifice through which gas may flow into the chamber even though said body restricts the efi'ective size of said inlet, and a pressure chamber about said tube and gas chamberfor air under pressure whereby air under pressure may flow through said tube and entrain gas from the gas chamber.

7. In combination, an entraining tube having a gas intake intermediate its ends and a gas chamber in communication with said gas intake, an apertured partition dividing the chamber into gas-receiving and gas-outlet compartments respectively, 7 a chambered body positioned in the gas-receiving compartment and adapted to restrict the efiec- "tive size of said aperture, said body having a relatively restricted orifice through which gas may flow from the gas-receiving compartment to the said chamber irrespective of whether or not said body restricts the effective size of the aperture in said partition.

8. In apparatus for mixing air and gas, the combination of a casing forming a pressure air chamber and having a nozzle-like intermediate its ends in communication with said gas chamber and having its inlet end in open communication with said pressure chamber, the discharge end of said tube projecting into said outlet and being in such space-relation therewith as to form an annular passage through which air may flow from within the .casing, and means supported by said casing for controlling the admission of gas into said gas chamber.

9. In combination, an entraining tube having a gas intake intermediate its ends, a gas chamber in communication with said gas intake, a casing forming an air chamber about said tube and gas chamber for air under pressure whereby air delivered to the air chamber the casing supported by the gas chamber.

within said castube and entrain gas and a valve structure'- for controlling the and a gas chamber wherein the gas intake, portion of said tube is mounted. In testimony whereof We aflix our signatures.

HUGH B. BARBER. WILLIAM M. HEPBURN.

gas-outlet compartment of v 10. In apparatus as claimed in claim 9, said I valve structurebeing ported to permit flow of gas at all times irrespective of whether the valve proper isclosed.

11. In apparatus adapted to utilize air under pressure to induce a flow of gas under lesser pressure, the combination of an enhaving a gas intake 1ntermed1- training tube ate its ends, an air casing wherein said tube is housed, said casing'having anoutlet in axial alinement with said tube, the discharge 7 end of said tube being positioned in said outlet andformin' therewith an annular passage throu h w 'ch air may flow from the casing, an means on the exterior of said 

